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Double stranded promoter region of BRAF undergoes to structural rearrangement in nearly physiological conditions
Author(s) -
Greco Maria Laura,
Folini Marco,
Sissi Claudia
Publication year - 2015
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2015.06.025
Subject(s) - promoter , antiparallel (mathematics) , transcription (linguistics) , chemistry , dna , gene , microbiology and biotechnology , biology , biophysics , stereochemistry , crystallography , gene expression , biochemistry , physics , linguistics , philosophy , quantum mechanics , magnetic field
The folding of oncogene promoters into non‐canonical DNA secondary structures is considered a strategy to control gene expression. Herein, we focused on a 30 bases sequence located upstream of the transcription start site of BRAF (Braf‐176) that contains 80% of guanines. We analyzed the structural behavior of the G‐ and C‐rich strands. By the use of spectroscopic and electrophoretic techniques we confirmed that they actually fold into a predominant antiparallel G‐quadruplex and into an i‐motif, respectively, and that they can coexist at nearly physiological conditions. Finally, the influence of several factors (KCl, pH, PEG 200 ) on the conversion of the double stranded form of the oncogene promoter into the two above mentioned non‐canonical structures has been explored.